kernel_optimize_test/Documentation
Michal Kubecek 10b518d4e6 ethtool: netlink bitset handling
The ethtool netlink code uses common framework for passing arbitrary
length bit sets to allow future extensions. A bitset can be a list (only
one bitmap) or can consist of value and mask pair (used e.g. when client
want to modify only some bits). A bitset can use one of two formats:
verbose (bit by bit) or compact.

Verbose format consists of bitset size (number of bits), list flag and
an array of bit nests, telling which bits are part of the list or which
bits are in the mask and which of them are to be set. In requests, bits
can be identified by index (position) or by name. In replies, kernel
provides both index and name. Verbose format is suitable for "one shot"
applications like standard ethtool command as it avoids the need to
either keep bit names (e.g. link modes) in sync with kernel or having to
add an extra roundtrip for string set request (e.g. for private flags).

Compact format uses one (list) or two (value/mask) arrays of 32-bit
words to store the bitmap(s). It is more suitable for long running
applications (ethtool in monitor mode or network management daemons)
which can retrieve the names once and then pass only compact bitmaps to
save space.

Userspace requests can use either format; ETHTOOL_FLAG_COMPACT_BITSETS
flag in request header tells kernel which format to use in reply.
Notifications always use compact format.

As some code uses arrays of unsigned long for internal representation and
some arrays of u32 (or even a single u32), two sets of parse/compose
helpers are introduced. To avoid code duplication, helpers for unsigned
long arrays are implemented as wrappers around helpers for u32 arrays.
There are two reasons for this choice: (1) u32 arrays are more frequent in
ethtool code and (2) unsigned long array can be always interpreted as an
u32 array on little endian 64-bit and all 32-bit architectures while we
would need special handling for odd number of u32 words in the opposite
direction.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-27 16:40:01 -08:00
..
ABI platform/mellanox: fix the mlx-bootctl sysfs 2019-12-20 19:00:50 +02:00
accounting
admin-guide Fixes for 5.5: 2019-12-22 10:59:06 -08:00
arm
arm64 arm64 updates for 5.5: 2019-11-25 15:39:19 -08:00
block block: add iostat counters for flush requests 2019-11-21 09:06:47 -07:00
bpf
cdrom
core-api powerpc updates for 5.5 #2 2019-12-06 13:36:31 -08:00
cpu-freq
crypto crypto: ablkcipher - remove deprecated and unused ablkcipher support 2019-11-17 09:02:49 +08:00
dev-tools selftests: Fix dangling documentation references to kselftest_module.sh 2019-12-11 10:27:01 -07:00
devicetree dt-bindings: ptp: Introduce MII time stamping devices. 2019-12-25 19:51:33 -08:00
doc-guide kernel-doc: rename the kernel-doc directive 'functions' to 'identifiers' 2019-11-07 13:17:25 -07:00
driver-api Merge branch 'thermal/next' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux 2019-12-05 11:21:24 -08:00
EDID
fault-injection
fb
features
filesystems overlayfs fixes for 5.5-rc2 2019-12-14 11:13:54 -08:00
firmware_class
firmware-guide
fpga
gpu drm/amdgpu: Improve RAS documentation (v2) 2019-11-06 16:27:48 -05:00
hid
hwmon Here's the main documentation changes for 5.5: 2019-12-02 11:51:02 -08:00
i2c Here's the main documentation changes for 5.5: 2019-12-02 11:51:02 -08:00
ia64
ide
iio
infiniband
input
isdn
kbuild kbuild: clarify the difference between obj-y and obj-m w.r.t. descending 2019-12-22 00:25:35 +09:00
kernel-hacking
leds
livepatch
locking
m68k
maintainer docs: fix up the maintainer profile document 2019-11-25 08:42:12 -07:00
media media: Documentation: media: *_DEFAULT targets for subdevs 2019-11-10 17:49:27 +01:00
mic
mips
misc-devices
netlabel
networking ethtool: netlink bitset handling 2019-12-27 16:40:01 -08:00
nios2
nvdimm libnvdimm, MAINTAINERS: Maintainer Entry Profile 2019-11-25 08:34:54 -07:00
openrisc
parisc
PCI
pcmcia
power pci-v5.5-changes 2019-12-03 13:58:22 -08:00
powerpc powerpc/fsl_booke/32: Document KASLR implementation 2019-11-13 19:27:58 +11:00
process treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
RCU
riscv
s390
scheduler
scsi scsi: smartpqi: Update attribute name to driver_version 2019-12-09 19:17:36 -05:00
security Documentation: security: core.rst: fix warnings 2019-11-22 10:01:47 -07:00
sh
sound ALSA: docs: Update about the new PCM sync_stop ops 2019-11-20 19:39:54 +01:00
sparc
sphinx docs, parallelism: Rearrange how jobserver reservations are made 2019-11-22 10:35:18 -07:00
sphinx-static
spi
target
timers
trace Here's the main documentation changes for 5.5: 2019-12-02 11:51:02 -08:00
translations treewide: Use sizeof_field() macro 2019-12-09 10:36:44 -08:00
usb
userspace-api Here's the main documentation changes for 5.5: 2019-12-02 11:51:02 -08:00
virt KVM: Add support for secure guests under the Protected Execution 2019-11-29 19:20:08 +01:00
virtual
vm mm/hmm: remove hmm_mirror and related 2019-11-23 19:56:45 -04:00
w1
watchdog
x86 Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-11-26 08:40:20 -08:00
xtensa
.gitignore
asm-annotations.rst
atomic_bitops.txt
atomic_t.txt
bus-virt-phys-mapping.txt
Changes
CodingStyle
conf.py
COPYING-logo
crc32.txt
debugging-modules.txt
debugging-via-ohci1394.txt
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt
DMA-attributes.txt dma-mapping: remove the DMA_ATTR_WRITE_BARRIER flag 2019-11-14 12:01:54 -04:00
DMA-ISA-LPC.txt
docutils.conf
dontdiff modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
futex-requeue-pi.txt
hwspinlock.txt
index.rst Here's the main documentation changes for 5.5: 2019-12-02 11:51:02 -08:00
io_ordering.txt
io-mapping.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
Kconfig
kobject.txt
kprobes.txt
kref.txt
logo.gif
lzo.txt
mailbox.txt
Makefile Kbuild updates for v5.5 2019-12-02 17:35:04 -08:00
memory-barriers.txt docs/memory-barriers.txt: Remove remaining references to mmiowb() 2019-11-22 10:00:46 -07:00
nommu-mmap.txt
padata.txt
percpu-rw-semaphore.txt
pi-futex.txt
preempt-locking.txt
rbtree.txt
remoteproc.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
speculation.txt
static-keys.txt
SubmittingPatches
tee.txt
this_cpu_ops.txt
unaligned-memory-access.txt
xz.txt